Drop offs where the whole family comes in?

Has anyone dealt with dog owners bringing the whole family into the house for a dog drop off? I get that the kids are curious and want to see where their dog will be vacationing, but parents are allowing them to walk all over my house, look in bathrooms, go upstairs, one kid even wanted to adjust my curtains! It's so uncomfortable. Typically, I want to usher them out as quickly as possible because dogs mark when they're new to a place and I can't monitor it with a family of 4 wondering around my home! I could meet them outside, but I don't want clients to think they're not welcome or that I'm hiding something. Anyone else have this problem?